Telephone-transmitter.



' 'Non 728,344 PATBNTED MAY 19,1903'.

G. E. WHEELER.

'TELEPHONE TRANSMITTER.

APPLIOA-TION FILED JULY 3l, 1992.

No MODEL. v z sums-SHEET L Q EMee/ef -PATBNTED 'MAY 19, 1903,

No. 728,344. l

T `G. E. WHEELER'.

TELEPHONE TRANSMITTER.v -APWPLIVATION FILED JU`LY 31, 1902.

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No MODEL.

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me Nan'ms wax-:ns co m Patented May 19, 1903.

UNITED STATES PATENT OEEICE.

GEORGE E. WHEELER, OF BURLINGTON, IOWA, ASSIGNOR TO MODERN ELECTRIC CO., OF BURLINGTON, IOWA.

lTELEPHONE-TRANSMITTER.

SPECIFICATION' forming part 0f Letters Patent N0. 728,344, dated May 19, 1903.

Application tiled July 3l, 1902. Serial No. 117.864. (No model.)

To all whom it may concern: ,1 f

Be it known that I, GEORGE E. WHEELER, a citizen of the United States, residing at Burlington, in the county of Des Moines and State of Iowa, have invented certain new and'useful Improvements in Telephone -Transmitters; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it. appertains to make and use the same.

This invention relates to improvements intelephone-transmitters of that kind employing a granular material in connection with electrodes for promoting the vibratoryaction under the sound-wave impulses imparted to the diaphragm. l

The invention has for its objects, first, to provide an improved construction and arrangement of the electrodes whereby both electrodes may be arranged inthe 'circuit to the exclusion. of the. diaphragm; second, to provide means whereby the parts may be adjusted to respond sym pathetically to the most delicate sound-waves without harshness from those of high intensity; ,third, to provide simple and eEectivev means for preventing packingof the granular material; fourth, to mount the electrodes and coacting parts in compact form and in such 'manner that they may be simultaneously removedifrom their casing for adjustment, renewal, or repairs, and, finally, to generally simplify the construction and increase the practical efficiency of transmitters of this type.

With these and other objects in View, which will readily appear as the nature of the invention is better understood, the same con-YY sists 1n certain novel features of construction and combination' and arrangement of parts, as will be hereinafter fully described, defined in the appended claims, and illustrated in the accompanying drawings, in which- Figure lis a side elevation of a transmittery embodying my invention. Fig. 2 is a vertical longitudinal section through the mouthpiece and diaphragm-chamber,on an enlarged scale. Fig. 3 shows in edge view two forms of agitators.

p Fig. 4 is a side elevation of the, cartridge containing the electrodes, &c. Fig.

5 is a cross-section of the same. Figs. 6 to 11, inclusive, are views illustrating various modifications in `the construction and arrangement of the-parts within the cartridgeshell, each figure showing a longitudinal and a transverse section of the form of cartridge represented thereby. f Fig. 12 is a similar view showing a modification of the general Vconstruction whereinthe cartridge-shell is dispensed with and the electrodes are arranged vertically instead of horizontally. Fig. 13 is an enlarged vertical section through the diaphragm, electrodes, and coperating parts removed fromthe casing. Fig/14 is a rear elevation of the same. Fig. 15 isa plan view of the open-work retainer for the granular material, showing the mannerin which end of the arm 1, and in the form 'shown in Figs. 1 and 2 this portion is extended forwardly to form a longitudinal chamber 8 for the reception of the electrodes'and coperating parts. The diaphragm9 is suitably mounted within the casing 2 and is pressed Vup'on'by the'damper-springs 10, which may .beof any preferred construction. f

- `The rear portion ot' thechamber 8 is interiorly tapered, and arranged withinsad casing is a' metallic shell or containeriOfpcomposed of a section 11 of uniform diameter, which lits snugly within the front part of the chamber S, and a section 12, tapered to fit within the rear portion of saidA chamber, whereby rearward displacement ofthe shell is prevented, the said two sections of `the shell being rigidly or detachablyunitedin any preferred manner. Inclosed within'the shell are two carbon electrodes 13 and 14, the electrode 13 being insulated from the shellby a layer of non-conducting material 15, while the electrode 14 is in direct contact with the wall of the shell, as clearly shown in Fig.,5.

The granular material '16 is interposed between the electrodes and is in contact therewith and with the shell. The electrodes, the granular material, and the insulation are held in proper relation by caps or disks 17 17', of mica or other non-conducting material, which close the ends of the section 11 of the shell.

Extending through the iller of granular material, which is in a more or less loose state, is a reciprocatory agitator 18, which has at its forward end a contact-piece 19, which projects through the front disk 17 and is adapted to be engaged by a button 2O on the diaghragm, and at its rear end a projection 21, which extends through the rear mica disk 17 and is in engagement with a stem 22, formed at its forward end with a head or collar 23 and mounted to slide at its rear end in an adjusting-nut 24, suitably mounted iu the rear end of the tapered section 12 of the shell. A coiled variable-resistance spring 25 surrounds the stem 22 between the head or collar 23 and the nut 24 and is adjustable to vary its resistance to the rearward movement ofthe agitator through the medium of said nut. Electrical connection with the electrode 13 is made through a spring-pressed contact 26, insulated from the casing by a non-conducting block 27, while electrical connection with the electrode 14 is made through the shell, diaphragm-casing, and transmitterarm. Thus the electrical connections with the two electrodes are made without the necessity of including the diaphragm in the circuit.

As the diaphragm 9 vibrates under theaction of the sound-waves the button 2O on each inward movement of the diaphragm taps the contact 19 on the agitator 18, thereby forcing said agitator rearwardly and transferring sympathetic motion to the granular material 16, the resistance of the agitator to such movement under the impulses of the diaphragm being regulated by the spring 25, which returns the agitator to its normal position on each outward movement of the diaphragm. By this means the parts are made to respond to the most delicate sound-waves and also to sound-waves of high intensity without indistinctness or harshness, but, on the contrary, with the greatest clearness, while the particles of the granular material are kept constantly in a free or loosened-up state and prevented from packing.

The tension of the spring 25 may be regnlated by means of the nut 24 to vary its resistance to the movement of the agitator and at the same time to adjust the transmitting parts to any desired degree of sensitiveness. Upon removing the cap and diaphragm the shell or cartridge with all the parts contained therein may be simultaneously removed from the chamber 8 for repairs, substitution, or removal of any of the parts without liability of disarrangement of said parts.

The granular material is preferably composed of particles of carbon of a desired size, but may be of particles of any other suitable equivalent substance or material.

As shown in Fig. 3, the agitator 18 may be of double-wedge form or uted or corrugated in order to give the particles of the granular material an undulating or irregular motion, thus preventing the particles from adhering or packing. This motion causes a change in the position of all the granules of the material by the alternate rise and fall of the same. Hence the outer particles or those most remote from the agitator are not allowed to pack, as might be the case if the agitator communicated motion only to the layers in immediate contact therewith. The agitator may, however, be of diamond form in crosssection, as shown in Figs. 5 and 7, or of any other approved form.

In Figs. G to 11, inclusive, I have shown modifications in the arrangement of the electrodes and granular material to suit Various conditions ct service,according to the voltage and amperage and the character of the telephone, whether of the local or long-distance type. In Figs. 6 and 7 the electrodes are insulated from the shell by a block or ring 28, of insulating material, which receives the electrodes and granular material, the two structures differing only in the form of the electrodes and arrangement of the granular material. In Fig. 8 the insulating-ring 28is also used; but three carbon electrodes 13', 132, and 142 are employed and "are arranged alternately with two layers 16' of the granular material. In Fig. 9 the arrangement of the electrodes and granular material is substantially that shown in Fig. 6; but both electrodes are in contact with the shell at diametrically opposite points, while the insulation 28 merely acts as a filler. In the construction shown in Fig.10 the outer carbon electrode 133 is of ring form and contacts with the shell and receives the inner electrode 131 and the interposed granular' material. Fig. 11 shows an arrangement similar to that shown in Figs. 2, 4, and 5, the only essential difference being that both the granular material and the inner electrode are insulated from the shell by the layer of insulating material. The electrical connections must necessarily be varied according to the form used. In each instance, it will be observed, a cartridge is provided, which carries the granular` material and electrodes and which is insertible and removable at will within and from the chamber S.

Figs. 12 to 15, inclusive, disclosea modification ot' the invention in which the essential variation consists in arranging the electrodes vertically instead" of horizontally. In this embodiment ot' the invention the diaphragm 92 is carried by a supporting-ring 30, of insulating material, to the rear face of which are secured yokes 3l 31. The electrodes 32 and roo yoke 31.

33 are, as stated, vertically arranged, vand the electrode 32 bears against-therear face of the diaphragm 92while the electrode 33 isY held spaced therefrom by the' interposed granular material 34, the granules or particles of which are made ofv comparatively large size and are retained within the cells or meshes of an open-work or foraminous holder or retainer 35, which'is preferably, though not necessarily, constructed'of crossed or intertwisted strands of wire. An insulated ring 34:2 closes the space between the electrodes` and securesv the retainer 35 against undue vertical play and also prevents any loss of particles of the carbon. The two electrodes and the interposed retainer are' apertu red for the reception of non-conducting bushings 33' 24', the latterheing slidably mounted upon a bolt 36and in -a guide-opening 343 in the the yoke 3l,with'its head bearingagainst the'front surface of the diaphragm 'and its rear threaded end loosely projecting through an opening in said yoke Stand engag'edbyV a clamping-nut 37, which bears against the yoke and holds the diaphragm seated within the supporting-ring 30. i

Bearing against ahead or collar'36 on the stem-bolt 36 is a coil-spring 3S, which surrounds the boltbetween said head and a disk' 39,'loosely mounted upon;l the bolt, the Vsaid disk 39 being adjustable through the medium of an adj listing-nut ELl0, working on the threads of the bolt for regulating 'the tension of said spring.

92 andhthrough the heady 3o, bearing on bushing 34', also forces the rear electrode forwardly, thereby holding thecarbongranules clamped with greater or less forcegbetween4 the two electrodes, so that said spring thus performs the dual function of regulating the vibration of the diaphragm andthe sensitiveness of the granular material, adapting them to be keyedV or tuned' torespond sympathet-y By ically to the most delicatesoundwaves. simply adjusting the nut i0 toward'or from the diaphragm the tension'of the spring may be increased or diminished at will to suitthe lates the sensitiveness yof the particles or granules of the granular material in sympathetic accord with the vibrations ofthe dia! phragm.

From the foregoingdescription, taken-in*` connection withthe accompanying drawings, it isthought that the construction, Inode of op- This bolt 36 extends: through thediaphragm, bushings, and central portion of By reference to Figyli it will beV seen that the spring` 38 exerts its resistance to therearward movement of`the`diaphragmv A rocatory agitator operatedfiu one direction by thediaphragrn anda'd'afptedrto impart motion*- K to thel particles ofthev granular"inaterialjandr means for opposingl fan' adjustable yieldingresistance to the movement of the diaphragm Vand agitator and operating the'latter in the reverse direction, substantially as described.

2. In a telephone-transmitter,a diaphragm,

electrodes, gran'ularvmaterial between" the electrodes, and an Aagitator operatedby`the impulses of the diaphragm and adapted" to impart undulatory movement to the particles of the granular material/substantially as described. e

3;In a telephone-transmitter, the combination of a diaphragm, electrodes,'granular 1material between the electrodes, a' stationary vholder f or thel electrodes and granular mate# rial', and means for opposing a'variablerevsistance to the inwardmovement of the diaphragm and regulating the sensitivenes'sfof Ythe granular material', said'means comprising an independently-movable agitator," a resist'- ance-spring acting thereon, and means for regulating the'tension of vsaid spring, substantially as described. y

4. Ina telephone-transmitter, the combi nation with a diaphragm, of electrodes, granu` lar `material between theelectrodeafa sta'- .tionary incl osure'for the electrodes andgranu# lar material, and means for opposing a resist'-v ance to the'inward'movementof the 'dias .phragm and regulating the sensitiveness of the ygranular material, said'means comprising a reciprocatory agitator, anda coperating threaded member, a resistance-springv regu*-l lating'the movement of the'agitato'rto corre'- spondin'glyregulate the vibrations ofthe diaphragm and the sensitiveness of the granular material, anda nut upon'thethreaded mem- ;ber for varying the tension of," said spring, Asubstantially as described. j Ar5."In""`a telephone-transmitter, the combi-f nation with a diaphragm, of electrodes, granula'r material between the electrodes, a sta-` tionary casing for t-lieelectrodes and granularV material,"anfag-itatorin the 'casing actuated by the vibrationsofy thedia'phragin for regulatingfor maintaining the sensitiveness ;of"the granular material, and meansforopv v Lposing anradjustable yielding resistance to inthe'f'orm, proportion,-

IOO

IIO

the movement of the diaphragm and agitator, substantially as described.

6. In atelephone-transmitter,a diaphragm, electrodes, granular material between the electrodes, a holder inclosing the electrodes and granular material, an agitator for the granular material, operated from the diaphragm and independently movable within the holder, a spring opposing a resistance to the movement of said agitator and means for adjusting the tension of said spring, substantially as described.

7. In a transmitter,a diaphragm,electrodes, granular material, a relatively stationary holder for the electrodes and granular material, a member movable under the impulses of the diaphragm to regulate the sensitiveness of the granular material, a resistancespring acting on said movable member, and

means for adjusting the tension of said spring, substantially as described.

8. An appliance for telephone-transmitters, comprising a cartridge-shell open at each end, electrodes therein, granular material between the electrodes, disks closing the ends of the shell and confining the electrodes and granular material, and an agitator extending through the granular material and having portions projecting through the disks, substantially as described.

In testimony whereof I have hereunto set my hand in presence of two subscribing Witnesses.

GEORGE E. WHEELER.

Witnesses:

J As. FITZGERALD, J. B. WooDsIDE. 

